Today is Linda's birthday and Candace tries to make it the best birthday ever. But every time she does, Phineas and Ferb beat her to it. Meanwhile, Dr. Doofenshmirtz tries to shrink everything that he hates so he never has to see them. --- Isabella's dog, Pinky, eats her Fireside Girls sash, so the boys build a mini-submarine to retrieve it, but they end up inside Candace instead. Perry is forced to take direct action when Dr. Doofenshmirtz's latest scheme specifically threatens Phineas and Ferb.